Parametric FE modeling of the compressive behavior of elliptically delaminated composite plates

• Κύριος συγγραφέας: Πριόβολος, Άγγελος
• Άλλοι συγγραφείς: Priovolos, Aggelos
• Γλώσσα: English
• Έκδοση: 2020
• Θέματα: Delamination; Residual compressive strength; Delamination propagation; Διαστρωματική αποκόλληση; Εναπομένουσα θλιπτική αντοχή; Διάδοση διαστρωματικής αποκόλλησης

Delaminations pose a potential threat towards the mechanical behavior of composites. Specifically, the presence of delaminations seems to have the most adverse effect on the compressional behavior of composites. Under the right conditions, such as load, delamination size, position and orientation, delamination growth may set in, which can have a catastrophic effect on the residual compressive strength of the affected structural part. The purpose of the present diploma thesis, is the development of parametric finite element (FE) models through python scripting for Abaqus, aimed at studying the compressive behavior of flat composite plates, with elliptical delaminations. Comparison with experiments for two separate delamination cases was carried out, regarding the residual compressive strength, aiming to validate the models. The delamination of the first case was “shallow” (positioned between the first and second ply of the plate), while the delamination of the second case was “deep” (positioned at the midplane of the plate). The error of FEA prediction with respect to the average experimental strength was 9.1 % and 21.71 % for the first and second case, respectively. The relatively significant error for the second case, probably stems mainly from significant deviation between the experimental data. Last, a prediction of pristine strength was made, though there were no experimental data, to compare to. For both delamination cases, there was negligible compressive strength reduction-0.064 % for the “shallow” and 4.35 % for the “deep” cases, respectively.